二叉树

最新推荐文章于 2024-07-29 08:47:18 发布

qq_52051345

最新推荐文章于 2024-07-29 08:47:18 发布

阅读量117

点赞数

CC 4.0 BY-SA版权

分类专栏：数据结构

本文链接：https://blog.youkuaiyun.com/qq_43469554/article/details/97509364

数据结构专栏收录该内容

2 篇文章

订阅专栏

本文介绍了二叉树的创建过程，包括初始化、存储结构定义及通过先序和中序遍历构建二叉树的方法。同时，详细展示了如何实现后序遍历算法，以获取二叉树的后序遍历序列。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

创建二叉树

#include<iostream>
class Node{
public:
    int data;
    Node *lchild, *rchild;
    Node(int _data){
        data = _data;
        lchild = NULL;
        rchild = NULL;
    }
};
class BinaryTree{
private:
    Node *root;
public:
    BinaryTree(){
        root = NULL;
	}
};
int main(){
    BinaryTree binarytree;
    return 0;
}

存储二叉树

#include<iostream>
class Node {
public:
    int data;
    Node *lchild, *rchild;
    Node(int _data) {
        data = _data;
        lchild = NULL;
        rchild = NULL;
    }

	~Node(){
	    if (lchild != NULL)
	    {
	        delete lchild;
	    }
	    if (rchild != NULL)
	    {
	        delete rchild;
	    }
	}
};
class BinaryTree {
private:
    Node *root;
public:
    BinaryTree() {
        root = NULL;
    }
	~BinaryTree(){
	    delete root;
	}
//存储二叉树 
	void build_demo()
	{
	    root = new Node(1);
	    root->lchild = new Node(2);
	    root->rchild = new Node(3);
	    root->lchild->lchild = new Node(4);
	    root->lchild->rchild = new Node(5);
	    root->rchild->rchild = new Node(6);
	}
};
int main() {
    BinaryTree binarytree;
	binarytree.build_demo();
    return 0;
}

已知先序和中序求后序

#include<iostream>
#include<string>
using namespace std;
class Node {
public:
    int data;
    Node *lchild, *rchild;
    Node(int _data) {
        data = _data;
        lchild = NULL;
        rchild = NULL;
    }
    ~Node() {
        if (lchild != NULL) {
            delete lchild;
        }
        if (rchild != NULL) {
            delete rchild;
        }
    }
    //后序遍历
    void postorder() {
        if (lchild != NULL) {
            lchild->postorder();
        }
        if (rchild != NULL) {
            rchild->postorder();
        }
        cout << data << " ";
    }
    //建立二叉树
	Node *build(const string &pre_str, const string &in_str, int len)
    {
        Node *p = new Node(pre_str[0] - '0');//根节点
        int pos = in_str.find(pre_str[0]);//根节点位置
        if (pos > 0)
        {//递归构建左子树
            p->lchild = build(pre_str.substr(1, pos), in_str.substr(0, pos), pos);
        }
        if (len - pos - 1 > 0)
        {//递归构建右子树
            p->rchild = build(pre_str.substr(pos + 1), in_str.substr(pos + 1), len - pos - 1);
        }
        return p;
    }
};
class BinaryTree {
private:
    Node *root;
public:
    BinaryTree() {
        root = NULL;
    }
    ~BinaryTree() {
        delete root;
    }
    //建立二叉树
	BinaryTree(const string &pre_str, const string &in_str, int len){
        root = root->build(pre_str, in_str, len);
    }
    void postorder() {
        root->postorder();
    }
};
int main() {
    string pre_str = "136945827";
    string in_str = "963548127";
	BinaryTree binarytree(pre_str, in_str, in_str.length());
    binarytree.postorder();
    cout << endl;
    return 0;
}

在这里插入图片描述